Battery module including thermal insulator disposed between battery blocks

Abstract

A battery module includes a plurality of battery blocks arranged in an X direction and thermal insulating boards that are each disposed between the battery blocks adjacent to each other in the X direction. The thermal insulating boards have a thermal insulating property. Each battery block includes a plurality of cylindrical batteries closely arranged in two or more rows in a staggered formation, with central axes of the cylindrical batteries being parallel to each other, and a block case entirely surrounding a periphery of a battery unit made up of the plurality of the cylindrical batteries so that the plurality of cylindrical batteries stays closely arranged.

The invention claimed is: 
     
       1. A battery module comprising:
 a plurality of battery blocks arranged in one direction; and 
 a thermal insulator disposed between the battery blocks adjacent to each other in the one direction, the thermal insulator having a thermal insulating property, wherein each of the battery blocks includes:
 a plurality of cylindrical batteries arranged in two or more rows in a staggered formation and central axes of the cylindrical batteries are parallel to each other, 
 a block case entirely surrounding and contacting a periphery of a battery unit made up of the plurality of cylindrical batteries such that movement of the plurality of cylindrical batteries is limited, 
 the plurality of cylindrical batteries includes a first cylindrical battery and a second cylindrical battery adjacent to the first cylindrical battery, and 
 an inner surface of a lateral wall of the block case contacts an outer surface of the first battery at a first location on the outer surface and does not contact a second location on the outer surface of the first cylindrical battery, wherein, at the second location, the first cylindrical battery contacts the second cylindrical battery. 
 
 
     
     
       2. The battery module according to  claim 1 , wherein the block case is made of a thermosetting resin containing a filler. 
     
     
       3. The battery module according to  claim 1 , wherein the thermal insulator includes a fiber sheet made of fibers and silica aerogel implanted into cavities of the fiber sheet. 
     
     
       4. The battery module according to  claim 1 , wherein the thermal insulator has a normal heat resistant temperature greater than or equal to a temperature that the block case achieves when thermal runaway occurs in the cylindrical batteries in the block case of one of the battery blocks. 
     
     
       5. The battery module according to  claim 1 , wherein
 a first lid part and a second lid part are provided to cover the plurality of battery blocks, 
 the first lid part and the second lid part are each made of a resin and have respective holes to expose electrode terminals of the cylindrical batteries, and 
 the electrode terminals of the plurality of cylindrical batteries accommodated in the battery blocks are electrically connected to current collector plates disposed at respective outsides of the first lid part and the second lid part. 
 
     
     
       6. The battery module according to  claim 1 , further comprising:
 a housing to accommodate the plurality of battery blocks inside; and 
 a fan,
 wherein the housing has an air inflow through-hole at a first side of the housing in the one direction and an air outflow through-hole at a second side of the housing in the one direction, and 
 the fan creates a current of air flowing into the housing through the air inflow through-hole and flowing out of the housing through the air outflow through-hole. 
 
 
     
     
       7. The battery module according to  claim 6 , wherein each of the battery blocks is positioned with the housing by a fastener that is disposed in a second gap created between the block case and the cylindrical batteries in planar view. 
     
     
       8. The battery module according to  claim 1 , further comprising a first lid part placed on an end of a first part of a battery block unit including the plurality of battery blocks in a direction of the central axes of the cylindrical batteries to align the plurality of battery blocks with each other in the direction of the central axes,
 wherein at least one of the first lid part and the block case is provided with a rib that at least partly overlaps the thermal insulator when viewed along a direction orthogonal to at least one of the one direction and the direction of the central axes. 
 
     
     
       9. The battery module according to  claim 8 , wherein the rib is provided on the first lid part, and
 the battery blocks adjacent to each other in the one direction are separated by the rib in the one direction. 
 
     
     
       10. The battery module according to  claim 8 , wherein
 the block case is made of a resin material having a thermal insulating property, 
 a plurality of the block cases incorporated in the battery block unit includes a ribbed block case provided with the rib projecting from a first end of the ribbed block case in the one direction, and 
 the rib is in contact with the block case adjacent to the first end of the ribbed block case in the one direction.